Possible to recalibrate the battery on a laptop?

So recently I've started to get this problem that the laptop dies even
when the battery indicator says there is something like 40% left, i.e.
I never get a low battery warning. Then when I plug it in and restart
it also says the battery is at something like 40%. The laptop is about
five years old.

Is it possible to recalibrate the battery indicator so I would get a
warning when it is about to die?

[old sixpack13]

...
 
>  Is it possible to recalibrate the battery indicator so I would get a
>  warning when it is about to die? 
I slightly remember I have seen something about it in the BIOS in one of my laptop (long
ago, though)

maybe this could help:
https://batteryuniversity.com/articles

[George N. White III]

On Thu, Feb 16, 2023 at 1:42 PM <andreas.fournier(a)runbox.com&gt; wrote:

>  So recently I've started to get this problem that the laptop dies
> even
>  when the battery indicator says there is something like 40% left, i.e.
>  I never get a low battery warning. Then when I plug it in and restart
>  it also says the battery is at something like 40%. The laptop is about
>  five years old.
>  
Battery "health" can't be described by one number.  Old batteries often
have high "internal resistance" which means they work fine under moderate
loads, but voltage will drop under high loads, causing a system crash.  This
is why batteries no longer viable for EV use can be repurposed for use in
backup systems where loads don't spike they way they do in an EV.


>  Is it possible to recalibrate the battery indicator so I would get a
>  warning when it is about to die?
>  
I think you are outside the envelope where recalibration (which is
more about the measuring device than the battery) is meaningful.

-- 
George N. White III

[Tim]

On Thu, 2023-02-16 at 18:41 +0100, andreas.fournier(a)runbox.com wrote:
>  Is it possible to recalibrate the battery indicator so I would get a
>  warning when it is about to die? 
I did that on my laptop, and it was the instant death of my battery.

Well, it was probably more that the sensors decided that the battery
only had 30 seconds of life to it, than anything else.
 
-- 
 
uname -rsvp
Linux 3.10.0-1160.83.1.el7.x86_64 #1 SMP Wed Jan 25 16:41:43 UTC 2023 x86_64
 
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[Roger Heflin]

Usually how battery packs die is that one of the cells becomes very
weak (this case), or goes high resistance (completely dead pack), or
shorts internally (you lose the voltage from one battery but the pack
will still work so long as the device can survive with much lower
voltages).

And basically that cell will go from about normal voltage 4.2V (or
whatever it is being charged to) to close to 0 quickly.   This causes
a sudden abnormal drop in the pack voltage and does not match the
normal voltage/capacity/discharge curve so not really predictable.

The solutions are to get a new battery pack, or carefully take the
current pack apart and figure out the bad cell and replace the bad
cell with a new similar cell.  You can typically get a 3rd party
battery for a reasonable price.

On Thu, Feb 16, 2023 at 9:33 PM Tim via users
<users(a)lists.fedoraproject.org&gt; wrote:
>
> On Thu, 2023-02-16 at 18:41 +0100, andreas.fournier(a)runbox.com wrote:
> > Is it possible to recalibrate the battery indicator so I would get a
> > warning when it is about to die?
>
> I did that on my laptop, and it was the instant death of my battery.
>
> Well, it was probably more that the sensors decided that the battery
> only had 30 seconds of life to it, than anything else.
>
> --
>
> uname -rsvp
> Linux 3.10.0-1160.83.1.el7.x86_64 #1 SMP Wed Jan 25 16:41:43 UTC 2023 x86_64
>
> Boilerplate:  All unexpected mail to my mailbox is automatically deleted.
> I will only get to see the messages that are posted to the mailing list.
>
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